Use of sodium citrate tribasic

ongarine

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I have a gift from a chemist friend: a container for about 1 Kg. of sodium citrate tribasic, he said that maybe I could use it in photo formulas.
Until now I have not find any formulas with sodium citrate tribasic.
Some of the photo chemists in APUG have some suggestions?
Thanks
 

sanking

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I use sodum citrate tribasic. 20% solution, as a developer for kallitype, but I add a small amount of citric acid to make the solution acidic.

Sandy
 

dancqu

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sanking said:
I use sodum citrate tribasic. 20% solution,
as a developer for kallitype, ... Sandy
Click to expand...

I think it must be quite alkaline. Not so much
though as tribasic phosphate. How about it as
the or a activator and or for ph buffering? And
what about sodium acetate? I wonder more
use of it is not made. Dan
 

sanking

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dancqu said:
I think it must be quite alkaline. Not so much
though as tribasic phosphate. How about it as
the or a activator and or for ph buffering? And
what about sodium acetate? I wonder more
use of it is not made. Dan
Click to expand...


In fact sodium citrate tribasic is not all that alkaline. The supply I get from www.thechemistrystore.com mixes up at about pH 7.0 - 7.5. I add just a few spoonfulls of citric acid per liter of a 20$% solution and the pH drops to around 6.0.

Sandy King
 

Jordan

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Kirk Keyes said:
Sodium; weak acid
citrate; weak base

Add them together, not a very acidic or basic compound.
Click to expand...

Actually, sodium citrate is the salt of a weak acid (citric acid) and a strong base (sodium hydroxide), and ordinarily solutions of salts like these are fairly alkaline due to 'hydrolysis' of the anion. I think the difference here is that only the first pKa of citric acid is "acid-like" -- each subsequent pKa is about 1.2-1.4 log units weaker.
 
OP
OP

ongarine

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Could it be use as activator or......I will conserve as a memory of a passed era: the wet photography process?
 
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